This invention relates to color television picture tubes of the shadow mask variety and more particularly to such a tube incorporating therein means for preventing or at least substantially reducing damage to the fragile shadow mask caused by physical shocks such as might occur during shipping of the completed tube. Color picture tubes of the type discussed herein generally comprise a face plate portion in the form of a dish with an upstanding circumferential wall. A cathodoluminescent screen of patterned phosphors emissive of different colors of light is formed on the interior of the face plate and a shadow mask, to aid in color selection, is releasably mounted in the face plate, adjacent to the screen but spaced therefrom. A funnel portion is attached to the face plate and terminates in a neck which contains one or more electron guns for providing a stream or streams of electrons to energize the phosphors, all as is well understood in the art.
The shadow mask usually employed in this type of tube comprises a relatively fragile foraminated mask portion which is attached to a relatively rigid frame. Mounting within the face plate is generally accomplished by means of a plurality of leaf springs attached to the frame which have an apertured free end which engages a stud or similar projection on the interior of the face plate. This mounting is necessary because insertion and removal of the mask is accomplished a number of times as the screen is being fabricated; however, particularly when a three point suspension is being utilized, this type of mounting allows substantial movement of the mask in a direction transverse to the longitudinal axis of the tube when the tube is subjected to physical shocks. Since modern tubes present a rectangular format and the tubes are shipped in packing cartons wherein a short side of the tube is down, such shocks occur frequently during shipping with sufficient severity to cause damage to the fragile mask, which results in the tube being unacceptable for use in a color television receiver.